SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97d776f6f111fb88ec746b8ad816c2d97545f23ca2f80ed85658b3e49ce1a572' 
  AND token = 'aAjp0ATri2Ge/gPzkunfB3UTDTpOTk4n7hoYMCtvgVs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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