SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1fe2be6c29efa9865e0f0b7e3449ded67af8e1f864b00ffef3fce1c4e6f4c24d' 
  AND token = 'cqlYI6+msYi8Uqv9jkHE8ka9d2ZHqrsjuJrBLR0RDJI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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