SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'af4fbac7e3b25ce1ae6885d4feb74e138c1a6f6e0cbedddf666674eb6be38da4' 
  AND token = 'CQioYcL1T9ttcNhUxFuDvCpwQfXtM5RG6EYq9V9Mu50=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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