SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e6f7f23cc7741550ef3453c2a4989f2cf5cab077ef47288e4ccf8c6123c8d13' 
  AND token = 'NkWVg+6/cU6P+KxUzrLnf4iLrRwZXMyYbZG9zjPulGE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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