SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c980d99a98cfb218b737126c2473f1bc643e03957c2b630e9bbad93940139c52' 
  AND token = 'zjS7uixhHmPKnqjd2l5KrsTzhZG258evodU7nYxOwmU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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