SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e817b918b80dc3b90076a3424bcbd69c73acf3e1d0809a9c686a268b384369e9' 
  AND token = '5inronX/j25j3yT4o+P2karZ3VrVrG99rDuh62SYRZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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