SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '62d1dc3ac9684e53ef85d982d00742a8db5070d13a9af4013b7a99ff47d58528' 
  AND token = 'GrginLDjW1hDedqHgrHkIBiKUQgsS+1UvL0zIjEvFgA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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