SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74e1b7fb87b49f45921a26b84ccfac2807d7e8701cb085f0e52be00624de9a77' 
  AND token = 'UBxqtVamHZHWDXzUrqZ27o1ZWqiOsQkqOa3kPDJVnEQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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