SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f91ec37d994abfd7020d72d380ccb40b2fafa7b2c30e9116fd7824acd0215ac' 
  AND token = 'qNkSCZyozV8GkuZlKGU65Fp6GMQW5igVXJJqjAXcVX4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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