SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03ea52ad4984dadaf1611f03a2f49ae8ec45ae1e25499f355793c8e0e915cd9d' 
  AND token = 'QlSDlJCVhMkas3y6S9Iu4Pf3gP2W9KV2Mssu4G/IxO8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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