SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f985f9d40902f512b7ce8d0b66fa67a2c68c050ba7a9747c90285734a320cbee' 
  AND token = 'jiFlxOWSenml4EN8E6gUIK4rAeHa7de0swWRp0DbmVk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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