SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2f97c1bbc1c6bda58b91166a25586697784276f38daf73bc4517898845833bd' 
  AND token = '0ddx4SOMjWhY4YDu6HK/YS7voMXX0PVZZ7Rf6h/rQHU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}