SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '738802eb3dd480881b6afb7bfd045420dc084f95f0822cc3c136bb48234a1d7c' 
  AND token = 'q7f4Qx5mmwZJyar7t71eMJl65m2H56Wy21YPepXx/Gw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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