SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e96aa8367e6cba31ccf32b274fa81a4379607f3db0bfbca6fc3784d88e021f66' 
  AND token = '4K9CnR/nCOq5kQmne/zgBfFn7AWW1OxkOpnubMH6UfA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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