SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '263548827b318e6fd2da78763e2123b5fffbe78d61d55d99778d4b580e9e05f0' 
  AND token = 'AVyRCF3rPeZx0pxhCtNtfZyjbNRKY+1EaiEgV3TVj9Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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