SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f877c82693ee4b7a969be8bd3109072b64bc336d5bf83fb80b6f2ca4a91c3c5f' 
  AND token = 'dSq7X9snkg3XZHkp2zmHGxjA2+bJGg9ZVrR2JVYgYwo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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