SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b14af96ff0f29642e8b9f5f43fab00025fd0f514bbdbb4b1df3724bf2e7be65c' 
  AND token = 'wGWE1f7VSkjGHxLUyIs6ptFnkPpopJ77LmIi3KD4J34=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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