SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '93aa591ee0e9b9d6e7ea9545c0ac3d390db82195a21cde9d81181cfe64163313' 
  AND token = 'hZvI5YY02r1AKo1cADpZOpws+rdf2Dbj6DBgnyOUHwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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