SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2a0471f71257f01bd03967c290231f4184e8c4fccd0521324d58a6660ec160f' 
  AND token = 'y3WDibFK2KOGGb/VAMYEf4MZrmYjPzROPqWOVE4BVTw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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