SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8843d79def5ab37f2f25b1d0560c2b444b64f50bad0a7fb8d75810dd92d02613' 
  AND token = '3wGnnzzkiagT7WOOO9n5FouS86y+knNWUnOhpcjHdaM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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