Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b3fd6b8b34b2e2fb19fe128f4ae8a83f5ad6eaae46460dbb8c4204ae6ca48c83' 
  AND token = '51sXhR5n5QEldaf3iWiNZODZ7KFbzDHnL1axJHhA6uE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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