SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ffc8f8d4230127e1f0b106f80ed778797694d1836e4a2c64bdd0b6e96a6c653' 
  AND token = 'TWhRjUdPSIlXgBI9j/umSLMVQ/rEtVUSpkBkFwhmqrc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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