SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7f24dc6d528631a0a121344d4b26101e4a28733cfabf70f19ca44126bae4346' 
  AND token = '5o2OReeZuVTuGFcN18V3F8ncB/Pol/FEo52A00Vn6s4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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