SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '078f5ceb28cce2bc504e9325da68687a02f6c23c5b0874702b9c18c8d37fe90a' 
  AND token = 'N4vsukLr8A9b5b4mrCvmfr4dZdIOWx0gW2QUjv7Yk3I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}