SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd0a6115c7d09021bc4723912d2f13d14a8cfc84a38418ff65f3d26a1174a059' 
  AND token = 'GRAbugXpB+rBMHlSALvrAZ/54KPPubfB6xF6K5yCnOs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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