SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e48b2c88143048507f58adc0a801fc0ecd35100f19e0c80774fd84bca5d2f1e2' 
  AND token = 'N1GyhWepOoDDiFRIfB4YUXDlyaiFkZDUOZSYwnOIQkU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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