SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '956e778fbf643395ded374263a39103f736418e5efbd3b674524b94892dec480' 
  AND token = '5Kw2FAgAXAoCWSEWeViyA6Tw/tLLvABzAmjgQLPGmRw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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