SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf5d452a484b022b32e845c2ccf3ab7635ce09629d0f9332f1631d87cf035c6d' 
  AND token = '2IsZtozGfM+hnxxmHa53cWFSCWPJDQqMunuwo+WQJ/4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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