SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e96abb471a5504df4653e6bf375618cd97568dd7f1a3e9698be9e7d3a73920e' 
  AND token = '0/shazkPXJsbiyM1fFGerZjazK3PPjy/Elfeel0pE4E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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