SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc1c40fa24333e4fff2690dc62a747507468b081edbcbcbfff72be4b840bc877' 
  AND token = 'jE4qqEN9wXUL5YChiKbXVTlZFZtTeu7dbtJsnbIQmNI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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