SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee4a58ab609711c121cd3dde06f66e68cf928195cfc7c2e005d5c690c3feb43c' 
  AND token = 'sYPYcMx+i99WLqSWJJXXU7QFtdtaI1AnKUO8KuDUwLs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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