SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf44de293145fe1c0f803732b0878a47bb59614aab13a066d320efc203e2514d' 
  AND token = 'q5T5fZS9db2lSPdo1x1V0Z1Jqi2/GZV4OsoiZLAZWuI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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