SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8428a4df766e6e22593631413b52a20435c48bac66c320fc8ca8c51840bf5797' 
  AND token = 'Af/W+tCJIhH8JLYoPC+FjgInU7FLszDyB+VJ2+NKaXc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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