SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08fa3e6c327e57593920c7e11cf962611d7b9e969ba9bcd355f612b40378b548' 
  AND token = 'B2UlX7L/OMIAqkDW1QpuaBVid65D2t2rdxw23hT73Fw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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