SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '457f329ced8c1b62969d4c850270344b5ef01da5852cdb7b793ed7251bb32e19' 
  AND token = 'n82k/iFoLOjCChipxlmOS3LZo0nhqhyKo4ParNJvQhU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}