SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '606dea81298dc773aea3897b3dccefca47b98b054f2dd95b5405cfd74182896f' 
  AND token = 'tGa3WesicIQOYcgRZhMBRcEEZwpJkS2XOoDTWwVpxO8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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