SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c6e86f4f1d4a1734ab23bfff14638dab88ee49bee07575ce425c46a4da8b8a1' 
  AND token = 'ICTOwI796xXfnfhvmDKbFMMX8FmXgOu9foJFxOkNGTY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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