SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfa49884b1954ea607c2832be16b26b46aead02234056d3b555fde3f8162662f' 
  AND token = 'hNSESlSnqEWzNhgxGQ5C9t2I5jI76BHFjVZBx4Fexbw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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