SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd0395c8871096fff0ae999ad7ad1fb335c14e30f97f9183f6bea66551998cd8' 
  AND token = 'ivcWvzUyhW97dRRAOnWtyqxYVZJTBz+ZBoQFWuIjrW8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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