SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '161868e723720bb7571d43d2650ea6024dbadee8421c53c0832b8ffe288adc4c' 
  AND token = 'MsVDiHTSivKw64P0poZO3UR4JprcY2Bu9EZyulvbfko=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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