SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a11aa51dc508cbe53312fb33fe7a850c69fe725f846274b875755fe722e5394' 
  AND token = 'Muxlb1te0HWbndO4Ki0xyRjHuofTwUJRHZJ3eEQGIO4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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