SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4a3a483c1e2946232b27327f9aa13cff2db8d31c1837e6a05753483b1df5c027' 
  AND token = '/ktEQZNZPMiLQFMACOlLZbBLq59mSU8UZ51P3a+JXMc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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