SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ded86ca81bf85fd49be027a40b7e2b396d72e4268d7cc6385a4f7ad737754469' 
  AND token = '0IyeEPaEryzYoLr4/wtqHL+kSSxRNZ/ttIuz2xDGKFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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