SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94538d55b66bd012d0e453dffe6555195f5eb94643cc6c1a7a9e69119fa4f389' 
  AND token = 'Obi8KczX0UkPbKCHXzhNKioEPaVyOl1caGb1LrKi4nI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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