SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4bf0aee95c02109b8175f0f70a3396c8d4027523e753e956bc3c81a85088bd8b' 
  AND token = '6Mh9LPuvE/RbZvto/8fMhZ79b0x2fMsg/0r1/ls8MwE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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