SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cb0e196487b6ad5c560d1a3d2d556a3fce27ebd69486ace819041c08d3148412' 
  AND token = 'iwdZdDcRlhAAfpATNlOBiwc/7Dl5ZfzEu8jELtiMJxg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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