SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c80b58d3d2d32479dd86be3dfe6502b3a1ee9ec2e971320c3ab96d5efc61c57a' 
  AND token = 'PQYZJon2D5CrBsw67i5vhz40qn+D6PDZ+WnKOcg1MXs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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