SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b0d6b3d7203937e85a0ecc9a9e8370b7c061352ff4a6f14b0a840757907352f6' 
  AND token = '1fKlm2zHatGiMXRVIoUvCt4Pha/ElSUUgDfxyELfK18=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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