SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd23dfcb7c970fa3f28f4b9b2523cb43b0f70962ed64b66374f086830609bf9c9' 
  AND token = 'GM2r8l36t+KqVzAN/tHHor/cHCb7yJOE4QppryLj/eU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}