SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32d2e48c5917162f32b5b559186e604a88bfcd40f7468e31017a6e471d1286bb' 
  AND token = '5OIxH8pD2Bl8RZHWyQhKPC7SggfGZPuMC5a+w1V3VPg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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