SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fecf816bdcb412c70a2024f54f90e8d72e0207bb3aa63fa190bdae59b86a895' 
  AND token = 'dK4HixnMD3zeqQJROWHKOFXZ7wYaKXKUu3tyf/IPXWY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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