SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b93933ff8c0c46a37f85bd11494f7d6453e768dc254c572e8718e7d4d03f050a' 
  AND token = 'pPUwFs7i8D0IBwVvjLhQAT5JLDrgv5mcxQb37uHabps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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