SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '57c72c5de8493294211cc0a257d591f82a1a969fd0c8e25482d222abe5da9dba' 
  AND token = 'KS/UU1zFpGkDNlA+9fFNAOn3wzsfI5u1IjKUbijrcpY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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