SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '178bb666088dc1d5830b7e50f5c11f3567d11b21de31da9fe1eaa2b589691475' 
  AND token = 'Qvt6AXfHaK/j/5dSzvkazQwOOMXcTsyszZDO5FKjHuo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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