SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29bf83a0f1777ea42be741679bb318c09e16cb1f54869d9b0e6dcd8354950be9' 
  AND token = 'ju5m6VyQU0eOZeoqcc/4rKQR/rGM3LSrJ+yfSlYpQ10=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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