SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e69647a2788ee0340fc5da0338598a86b287e52e78fb93313475d567dfad51f8' 
  AND token = 'aHoxZoJewSUVqeZ+4aX7CsGvKU2Pc2lVusFDaiZrAtQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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