SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf48ce424d7d1f18de18ea435ed063dbd8622ff311ebacf1e2072c7ccfabed9b' 
  AND token = 'Bh9/LRqdn6rSKTfhW6ZNr3Ul5fQfOa2VrJFYu6ZZqS4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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