SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c30b9c707c3334f1f2a6794365f31bb262fd28b8df1210920114ee1134256b13' 
  AND token = 'u346DoCn8HGowbvptQ+spOAOL/tV6T/KC5wzh/QPJIo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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