SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9806159f305cd5a168118bf064e42d71cb72d4b57d5f379af29e2d3e2f68aaa' 
  AND token = 'YIJAIirKM6eQswyf3D53sE4U3rCGEEmEaHMwiKTnvyQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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