SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a43aad01115a050872d38359b2cb9d0b8179357d652ed57174c59bf4b47e90ed' 
  AND token = 'FKsNo5Nm6DaIBqVqyQnMrwX2AqZOtAsd2Butf5cxQ/0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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