SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a60bc72019f22fc690482d50cae98d2b49cfe67e8e4a424d8fc6537fd6f0e308' 
  AND token = 'QPhviKWS09uox+x3sqQVYw7OLjzGsAR8I1gJVpRJ6Sg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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