SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '898a1bd6b92e11a553d5c27be3dd2e15b8299381faf2e71857a033cc9177dd51' 
  AND token = 'qBmDi28+LKx2hekq4q4VPIzjLRavGMzTJF2Zyu/dFY8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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